Medical-device guidance system

Abstract

A situation where a medical device is outside a region suitable for guidance control thereof can be easily coped with. Included are a medical device provided with a magnet; a guiding unit ( 5 X- 1, 5 X- 2, 5 Y- 1, 5 Y- 2, 5 Z- 1, 5 Z- 2 ) that forms a control magnetic field for guidance control of the medical device, inside a prescribed control area; a detection unit ( 7 Y- 1, 7 Y- 2 ) that detects positional information of the medical device; and a computational unit that judges that the medical device has gone outside the control area on the basis of an output from the detection unit ( 7 Y- 1, 7 Y- 2 ) and calculates a direction for returning the medical device to the control area, wherein a signal-waveform calculating unit ( 21 ) stops forming the control magnetic field when the medical device is outside the control area.

1. A medical-device guidance system comprising:
 a medical device with a magnet; 
 a guiding unit that forms a control magnetic field for guidance control of the medical device, inside a prescribed control area; 
 a detection unit that detects positional information of the medical device; 
 a computational unit that judges that the medical device has gone outside the control area on the basis of an output from the detection unit and that calculates a direction for returning the medical device to the control area; and 
 a control unit that controls the guiding unit on the basis of an output from the computational unit, 
 wherein the control unit stops formation of the control magnetic field when the medical device goes outside the control area. 
 
     
     
       2. A medical-device guidance system according to  claim 1 , wherein the medical device is configured to be introduced into a body cavity of a subject, and
 a driver is provided that moves the subject on the basis of an output from the control unit. 
 
     
     
       3. A medical-device guidance system according to  claim 1 , wherein on the basis of the output from the computational unit, the control unit forms the control magnetic field for moving the medical device by a prescribed amount in the direction for returning the medical device to the control area and thereafter stops forming the control magnetic field. 
     
     
       4. A medical-device guidance system according to  claim 1 , wherein the medical device includes a detected portion to be detected by the detection unit, and
 the detection unit is disposed in the vicinity of a boundary region of the control area. 
 
     
     
       5. A medical-device guidance system according to  claim 1 , wherein:
 the medical device includes a magnetic induction coil; and 
 the detection unit includes a position-detection-magnetic-field forming unit that forms a position-detection magnetic field for inducing an induced magnetic field in the magnetic induction coil, 
 a magnetic-field detection unit that detects the induced magnetic field generated by the magnetic induction coil, and 
 a position calculating unit that calculates positional information of the medical device on the basis of an output from the magnetic-field detection unit. 
 
     
     
       6. A medical-device guidance system according to  claim 1 , wherein:
 the medical device includes a magnetic-field generator that generates a magnetic field; and 
 the detection unit includes
 a magnetic-field detection unit that detects the magnetic field generated by the magnetic-field generator, and 
 a position calculating unit that calculates positional information of the medical device on the basis of an output from the magnetic-field detection unit. 
 
 
     
     
       7. A medical-device guidance system according to  claim 1 , wherein:
 the medical device includes a wireless transmission unit that transmits radio waves; and 
 the detection unit includes
 a plurality of wireless reception units that receive the radio waves, and 
 a position calculating unit that calculates positional information of the medical device on the basis of output signals from the plurality of wireless reception units. 
 
 
     
     
       8. A medical-device guidance system according to  claim 1 , wherein:
 the medical device includes a metal portion; and 
 the detection unit includes a metal detection unit that is responsive to the metal portion and a position calculating unit that calculates positional information of the medical device on the basis of an output from the metal detection unit. 
 
     
     
       9. A medical-device guidance system according to  claim 1 , wherein:
 the medical device includes an ultrasonic-wave reflecting portion; and 
 the detection unit includes an ultrasonic-wave detection unit that detects ultrasonic waves reflected at the ultrasonic-wave reflecting portion, and a position calculating unit that calculates positional information of the medical device on the basis of an output from the ultrasonic-wave detection unit. 
 
     
     
       10. A medical-device guidance system control method for guidance control, by a control magnetic field formed in a control area, of a medical device in which a magnetic field can be induced and which is disposed inside the control area, the medical-device guidance system control method comprising:
 a detecting step of detecting positional information of the medical device; 
 a calculating step of judging that the medical device has gone outside the control area and calculating a direction for returning the medical device to the control area; 
 an instructing step of outputting an instruction for moving the medical device in a direction for returning the medical device to the control area; and 
 a stopping step of stopping formation of the control magnetic field when the medical device goes outside the control area. 
 
     
     
       11. A medical-device guidance system control method according to  claim 10 , further comprising:
 between the instructing step and the stopping step, 
 a moving step of relatively moving the medical device and the control area by a prescribed amount in a direction for returning the medical device to the control area. 
 
     
     
       12. A medical-device guidance system, comprising:
 a medical device provided with a magnet; 
 a guiding unit that forms a control magnetic field for guidance control of the medical device, inside a prescribed control area; 
 a detection unit that detects positional information and/or directional information of the medical device inside the control area; 
 a second detection unit that detects positional information of the medical device inside the control area and outside the control area; 
 a computational unit that judges that the medical device has gone outside the control area on the basis of an output from the second detection unit; and 
 a control unit that controls the guiding unit on the basis of an output from the computational unit, 
 wherein the control unit stops formation of the control magnetic field when the medical device goes outside the control area. 
 
     
     
       13. A medical-device guidance system according to  claim 12 , wherein the computational unit further calculates a direction for returning the medical device to the control area. 
     
     
       14. A medical-device guidance system according to  claim 13 , wherein the operating state of the detection unit is controlled on the basis of the output from the second detection unit. 
     
     
       15. A medical-device guidance system according to  claim 12 , wherein the control unit determines the control magnetic field generated by the guiding unit on the basis of the positional information and/or the directional information detected by the detection unit. 
     
     
       16. A medical-device guidance system according to  claim 12 , wherein the detection precision of the positional information from the detection unit is better than the detection precision of the positional information from the second detection unit. 
     
     
       17. A medical-device guidance system according to  claim 16 , wherein the detection unit is formed of a magnetic sensor, and the second detection unit is formed of a metal sensor. 
     
     
       18. A medical-device guidance system according to  claim 17 , wherein the magnetic sensor and the metal sensor detect the positional information on the basis of magnetic fields of different frequencies.